Title: EFFECTS OF INDUSTRIAL BYPRODUCTS CONTAINING HIGH ALUMINUM ON IRON LEVELS ON PLANT RESIDUE COMPOSITION
Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 17, 2003
Publication Date: May 1, 2004
Citation: Sikora, L.J. 2004. Effects of industrial byproducts containing high aluminum on iron levels on plant residue composition. Communications in Soil Science and Plant Analysis. 35:921-936.
Interpretive Summary: Excess soluble phosphorus in soils and manures has forced farmers to search for ways to control the addition of phosphorus to soils. Because phosphorus becomes less soluble in the presence of iron, aluminum or calcium, addition of industrial byproducts containing these metals may help reduce the soluble phosphorus content of manures or soils. But care must be taken to ensure that, when controlling phosphorus with industrial byproducts, you are not harming the soil or water. Studies were conducted to determine if two industrial byproducts that reduce soluble phosphorus may affect an important biological process in soil. Plant residue decomposition was monitored in two soils amended with water treatment residue (WTR) containing high amounts of aluminum or iron rich residue (IRR). Neither residue affected plant decomposition in Matapeake soil loam which had a pH of 6.8. The IRR affected soil and plant residue decomposition in Sassafras soil which has a pH of 5.1. Adjusting the pH with CaO corrected the decline in soil decomposition, but plant residue decomposition affects appeared not related to pH or salts. These data suggest that byproduct amendment to soil may affect the biological processes in soil while correcting the excess phosphorus problem. A bioassay for industrial byproduct addition may be helpful in foreseeing problems that may occur in their use.
Excess P in soils is a result of manure and fertilizer additions that exceeded crop P requirements. To reduce or eliminate future P fertilizer additions or manures is one remediation step. Another would be to treat manures or soils with byproducts that contain Fe, Al or Ca that adsorb P readily. A study was conducted in which two industrial byproducts were added to two soils and 14C-labeled soybean leaves and stems degradation and soil decomposition were monitored. Water treatment residue (WTR) containing high Al content and iron-rich residue (IRR) were added to Sassafras and Matapeake soils at rates form 0.5 to 10.0 g kg-1soil. Lime (CaO) was added as a treatment to determine the effect of increased pH. Additions of WTR to either soil did not affect decomposition of 14C-labeled soybean leaves and stems, soil decomposition recorded by total CO2 or residual soil 14C. Addition of IRR affected decomposition of 14C-labeled soybean leaves and stems, soil decomposition recorded by total CO2 and residual soil 14C. Although no one factor explained the effects on decomposition, salinity may be a factor as well as pH. Lime addition corrected the low soil decomposition as result of 10 g kg-1 IRR amendment. Lime also reduced salinity about 20%. Remediation of high P soils or treatment of manure is beneficial, but additional tests on biological effects on industrial byproduct addition may be necessary.